P 32: Proceedings of the American Academy of Arts and
Sciences 7 (1868):287-98. [Also published in W2:49-9 (with the four
other papers in the so-called PAAAS Series and with references to related
manuscripts published in W1) and in CP1.545-59. Peirce completely rewrote
the paper to serve as the opening chapter of his 1894 "How to Reason"
(MS 403).] Presented to the Academy on 14 May 1867, this paper is, according
to Peirce, "perhaps the least unsatisfactory, from a logical point of
view, that I ever succeeded in producing" and, with item 3 below, one
of his two "strongest philosophical works." The culmination of a ten-year
effort and the keystone of Peirce's system of philosophy, it argues for
a new post-Kantian set of categories (or univeral conceptions) by demonstrating
that they are required for the unification of experience. Peirce's argument
is essentially a logical derivation, though it depends on a type of mental
separation he called 'prescision,' which is also required for his later
phenomenological derivation of the categories.

P 26: Journal of Speculative Philosophy 2 (1868):103-14.
[Also published in W2:193-211 (with related letters and earlier attempts
at this article and the two that follow) and in CP 5.213-63.] Item 2 is
the first of three articles usually referred to as the JSP Cognition
Series, in which Peirce develops some of the results and consequences
of item 1 and attempts "to prove and to trace the consequences of certain
propositions in epistemology tending toward the recognition of the reality
of continuity and of generality and going to show the absurdity of individualism
and of egoism. " (In "The Law of Mind" [item 23], he indicates that this
is an early attempt at developing his doctrine of synechism.) Peirce's
opposition to Cartesianism results in the following four denials: (1)
we have no power of introspection, but all knowledge of the internal world
is derived by hypothetical reasoning from our knowledge of external facts,
(2) we have no power of intuition, but every cognition is determined logically
by previous cognitions, (3) we have no power of thinking without signs,
and (4) we have no conception of the absolutely incognizable.

P 27: Journal of Speculative Philosophy 2 (1868):140-57.
[Also published in W2:211-42 and in CP 5.264-317.] With item 1 above,
one of Peirce's two "strongest philosophical works," this article develops
an account of mind and reality from the ground prepared in item 2. Peirce
asserts that all mental events are valid inferences, and claims that as
every thought is a sign, so man himself is a sign. He also gives a fairly
detailed account of his theory of signs as of 1868, and makes his first
published declaration for scholastic realism. (Peirce's philosophy of
mind as developed here is, according to Christopher Hookway, a type of
functionalism.)

4.
Grounds of Validity of the Laws of Logic: Further Consequences of Four
Incapacities

P 41: Journal of Speculative Philosophy 2 (1869):193-208.
[Also published in W2:242-72 and in CP 5.318-57. Changes in an offprint
(MS 593), prepared as essay 6 of his 1893 "Search for a Method," are recorded
in the Notes.] In this article, the culmination of the Cognition Series,
Peirce works out a rationale for the objective validity of the laws of
logic and, by linking epistemology with a social theory of logic, grounds
induction in altruistic sentiments. He also discusses a version of the
liar paradox and offers a solution based on the supposition that "every
proposition asserts its own truth, " and he makes his first published
reference to De Morgan's work on the logic of relations.

P 60: North American Review 113 (October 1871):449-72.
[Also published in W2:462-87 (with Chauncey Wright's criticism and Peirce's
response [pp. 487-90) and in CP 8.7-38.] In what may be the most important
of all his reviews, Peirce discusses the realist-nominalist controversy
(which he believed to be of fundamental significance for philosophy as
well as life) and gives a detailed account of his already slightly modified
scholastic realism. Peirce's common-sense account of truth and reality
contains important elements of his developing pragmatism.

6.
On a New Class of Observations, Suggested by the Principles of Logic

MS 1104. [First published, as MS 311, in W3:235-37.]
Written in the summer of 1877, apparently for presentation, this brief
paper recommends the observational study of sensations (as Peirce recommended
for all sciences, even mathematics). Opposed to the "ordinary" view that
"there are ultimate sensations without any general relations between them,"
Peirce argues that, although we can never completely capture in general
descriptions the differences between different sensations, we can "make
an indefinite progress toward such a result." But if that is unconvincing,
Peirce goes on to say, perhaps we should try a phenomenological approach.
Whether there are pure and completely determinate individual sensations
is a question that can be dealt with by observational science; "here then,"
he concludes, "is a whole world of observation, to which we have been
systematically blind, simply because of a wrong metaphysical prejudice."

P 107: Popular Science Monthly 12 (November 1877):l-15.
[Also published in W3:242-57 (with parts of earlier versions, MSS
187-189 [pp.22-28]) and in CP 5.358-87. Peirce intended to use this paper
as essay 8 of his 1893 "Search for a Method," as chapter 5 of his 1894
"How to Reason" (MS 407), and as the first essay in his 1909/10 "Essays
on the Reasoning of Science" (MS 334). Substantive changes in these two
are recorded in the Notes; for the handwritten sections in MS 407 and
the changes taken from an offprint that is no longer extant, see the CP.]
This is the first of a series of six papers, collectively titled "Illustrations
of the Logic of Science"; at least one more paper was projected, and they
were once listed as a forthcoming book in Appleton's International Scientific
Series. The objective of the "Illustrations" is "to describe the method
of scientific investigation," and they contain, as Peirce later recalled,
"the earliest formulation of a method of logical analysis that [I] had
had the habit of alluding to as [my] pragmatism,'" or "the tiny seed that
under the culture of richer minds, grew into the goodly tree of that same
appellation that already begins to afford a comfortable and wholesome
lodge for many a soul." In the first paper, he develops his thesis that
thought is a form of inquiry, and belief the cessation of doubt, and he
emphasizes the self-corrective nature of the scientific method. He further
discusses four methods of fixing belief (those of tenacity and of authority,
the a priori method, and the method of science) and argues that only the
fourth, which alone appeals to an "external permanency," can lead to success
in the long run.

P 119: Popular Science Monthly 12 (January 1878):286-302.
[Also published in W3:257-76 and in CP 5.388-410. Peirce intended to use
this paper as essay 9 of his 1893 "Search for a Method" and as chapter
16 of his 1894 "How to Reason" (MS 422); the changes in MS 422 are recorded
in the Notes.] Written between 13 and 24 September 1877, while Peirce
was sailing to Plymouth, England, this paper criticizes Descartes' doctrine
of the clearness of ideas and goes on to develop Peirce's own theory,
according to which there are three levels or grades of clearness. The
theory of meaning associated with the third grade of clearness is represented
in the pragmatic maxim (and is sometimes thought of as an operationalist
theory). Peirce ends the paper by applying the pragmatic maxim in his
examination of the meaning of several conceptions, including 'realism'.
(He later thought that his early pragmatism was too nominalistic.)

P 120: Popular Science Monthly 12 (March 1878):604-15.
[Also published in W3:276-89 and in CP 2.645-60. Although the third and
fourth "Illustrations" were intended as one paper, the PSM editors
published it in two parts in two successive months. In 1893, Peirce retyped
the third paper to serve as essay 10 of "Search for a Method" and chapter
18 of "How to Reason" (MS 424) and, in 1910, he wrote several "Notes to
C.S.P.'s Third Paper in the Pop. Sci. Monthly. 1878, March" (in MSS 703
and 704); some of the changes in the typescript and one of the notes of
1910 are recorded in the Notes.] In an early discussion of what will later
become his synechism, Peirce argues that the assumption of continuity
provides a powerful engine for logic, and he develops his theory of probabilities
as the science of logic quantitatively treated (or as general logic).
To be logical Peirce says, men must not be selfish, for logic requires
the identification of one's interests with those of an unlimited community.
(Peirce also discusses the probability of a non-repeatable event in a
case that Hilary Putnam has named "Peirce's Puzzle.")

P 121: Popular Science Monthly 12 (April 1878):705-18.
[Also published in W3:290-305 and in CP 2.669-93.] In this paper, Peirce
continues to develop his theory of probability and gives rules for calculating
the probability of multiple events. He compares the conceptualistic view
(which refers probabilities to events) with the materialistic view (which
makes probability the ratio of the frequency of favorable cases to all
cases) and differentiates chance from probability. He argues for the frequency
view (which he held until nearly the turn of the century) and then connects
his views on probability with the nature of inductive (or synthetic) reasoning
and the problem of induction, for which be considers the need for an appeal
to possible worlds.

P 122: Popular Science Monthly 13 (June 1878):203-17.
[Also published in W3:306-22 and in CP 6.395-427.] In the fifth "Illustrations"
paper, Peirce argues against Mill's view that the uniformity of nature
is the sole warrant for induction and for the theory set out in the preceding
paper: that induction should be explained by the doctrine of probabilities
(which, as he points out, should pose no problem for religion). He also
proclaims, as he did throughout his life, that "the mind of man is strongly
adapted to the comprehension of the world," a capacity explained as the
result of natural selection and as being fundamental for success in abductive
reasoning (or hypothesis). Finally, he turns to some of the cosmological
questions that open the line of inquiry that will eventually result in
his guess at the riddle of the universe.

P 123: Popular Science Monthly 13 (August l878):47O-82.
[Also published in W3:323-38 and in CP 2.619-44.] Peirce concludes his
six "Illustrations" with a discussion of the three kinds of reasoning
(deduction, induction, hypothesis) based on the general form of syllogistic
argument composed of rule, case, and result. With examples from the history
of science, he demonstrates that hypothesis is different from induction
proper in that "hypothesis supposes something of a different kind from
what we have directly observed, and frequently something which it would
be impossible for us to observe directly," while induction only "infers
the existence of phenomena such as we have observed in cases which are
similar."

P 167: American Journal of Mathematics 3 (1880):15-57.
[Also published in W4:163-73 (with two earlier versions of part of the
first chapter, MSS 350 and 354 [pp. 38-46], and a fragmentary continuation
of the whole article, which ends with "to be continued," in MS 371
[pp. 210-11) and in CP 3.154-81. (Three further attempts at a continuation
are in W5:107-15.)] This article holds a place of some importance in the
history of formal logic and mathematics. In what is published here from
the first chapter, Peirce discusses the relationship between thinking
and cerebration (or logic and physiology), formulates the theory for his
logic of the copula employing statements of inclusion rather than Boolean
equations, and places some of his important epistemological conceptions
into the context of formal logic. (Item 16 represents the subsequent stage
of his development of this part of the algebra of logic and should be
read in conjunction with item 13.)

P 225: Johns Hopkins University Circulars 2:19
(November 1882):11-12. [Also published in W4:378-82, in CP 7.59-76, and
in HPPLS 940-44.] In this "Outline of the Remarks made by Prof. C. S.
Peirce, at the beginning of his Course, September, 1882," Peirce reflects
on the achievements of Darwin (who had died in April) and attributes them
mainly to Darwin's method. In describing the lecture to his eldest brother,
James Mills, in a 4 October 1882 letter, Peirce said: "I spoke of our
time as the age of method and said that the highest honors could no longer
be paid to the mere scientific specialist but to those who adapted the
methods of one science to the uses of another. That a liberal education
so far as it regards the intellect means logic, considered as the
method of methods,the via ad principia methodorum. That the student
ought to feel from the beginning to the end of his course, that in whatever
lecture room he is, it is logic he is studying." Peirce is now
defining his task as applying the methods of logic, especially induction
and hypothesis, to philosophy and science.

MS 875. [First published, as MS 494, in W4:544-54.]
Written in December 1883/January 1884, this fragmentary manuscript was
used for a lecture entitled "Design and Chance," given before the Johns
Hopkins University Metaphysical Club on 17 January 1884. Despite its brevity
and incompleteness, it represents a major advance in Peirce's progress
toward his guess at the riddle of the universe, and it marks the beginning
of his evolutionary explanation of the laws of nature (and his architectonic
metaphysics detailed in items 21-25). By the hypotheses of absolute chance,
habit-taking, and universal evolution, Peirce extends the postulate that
"everything is explicable . . . in a general way."

16.
[from] On the Algebra of Logic: A Contribution to the Philosophy of Notation

P 296: American Journal of Mathematics 7 (1885):180-202.
[Also published in W5:162-90 (with several related manuscripts, MSS 506-508
and 538-539 [pp. 107-16 and 191-220]) and in CP 3.359-403.] This paper,
which Peirce first presented (at least in part) at the 14-17 October 1884
meeting of the National Academy of Sciences in Newport, RI, consists of
four parts, and it is recognized as a substantial contribution to modern
logic and to the philosophy of logic and the theory of notation. In the
first part published here, Peirce considers the different kinds of signs
required for a fully adequate logic notation, and he concludes that it
is necessary to have tokens (conventional or general signs, usually called
symbols), indexes (demonstrative signs), and icons (signs of resemblance).
This is the first published appearance of the icon-index-symbol trichotomy
and Peirce's first application of his theory of signs to his algebraic
logic.

17.
An American Plato: Review of Royce's Religious Aspect of Philosophy

MS 1369. [Published, as MS 541, in W 5:221-34 and in CP
8.39-54 (without the opening paragraph).] Written for the Popular Science
Monthly in the summer of 1885 (but rejected by the editor, E. L. Youmans),
this lengthy review is, according to Peirce's 28 October 1885 letter to
William James, "something really very good." After praising Royce for
his style of reasoning, which is like Plato's, Peirce criticizes his idealism
as being too much like Hegel's, whose "capital error . . . which permeates
his whole system . . . is that he almost altogether ignores the Outward
Clash." Peirce repeats the thesis of item 16, that three kinds of signs
are indispensable in all reasoning, and emphasizes that indexes are necessary
to refer to individuals: "One such index must enter into every proposition,
its function being to designate the subject of discourse." (According
to Max Fisch, items 16 and 17 mark an important stage in Peirce's passage
from a one-category to a two-category realism.)

MS 897. [First published, as MS 572, in W5:292-94; see
also MSS 545, 546, 548, 573, 575, 578, and 582.] Sometime in 1885, it
occurred to Peirce that he may have found the key to the secret of the
universe, and he wrote to William James on 20 October: "I have something
very vast now . . . It is . . . an attempt to explain the laws of nature,
to show their general characteristics and to trace them to their origin
& predict new laws by the laws of the laws of nature." He then made his
famous 'guess': "three elements are active in the world, first, chance;
second, law; and third, habit-taking. Such is our guess of the secret
of the sphynx." It remained for him to work the details and consequences
of this grand hypothesis into a full-fledged theory. The present paper,
written in the summer of 1886 for a book to be entitled "One, Two, Three,
" is one of several attempts to organize the principal claims needed to
support his guess (and is an early version of the first chapter of item
19).

MS 909. [First published in CP 1.354 (the opening outline),
1.1-2 (the next two paragraphs), 1.355-68 (chapter 1), 1.373 (chapter
3), 1.374-75 and 379-83 (chapter 4; missing are the final sentence of
the second paragraph, the third paragraph, and the first half of the fourth
paragraph), and 1.385-416 (chapters 5, 6, and 7). An earlier opening page
has the title "Notes for a Book, to be entitled 'A Guess at the Riddle,'
with a Vignette of the Sphynx below the Title."] Although chapters 2,
8, and 9 are missing (and probably were never written) and chapter 3 is
a mere outline, 'A Guess at the Riddle" is perhaps Peirce's greatest and
most original contribution to speculative philosophy, and it marks his
deliberate turn to architectonic thought. His three categories, which
he speculates are isomorphic with the three elements that are active in
the universe (chance, law, and habit-taking), serve as the structure for
organizing the branches of philosophy and science, and it is clear that
he anticipated a complete reorganization of human knowledge around his
triad of universal conceptions; for as he wrote, on a variant opening
page, "this book, if ever written, as it soon will be if I am in a situation
to do it, will be one of the births of time." Although, unfortunately,
Peirce never was in such a situation, it is fortunate that many of his
major ideas in the "Guess" would soon appear in the papers of the Monist
Metaphysical Series (items 21-25).

MS 1600. [Previously unpublished.] Written (probably for
oral presentation) in early 1888 shortly after the completion of item
19, this three-page typescript found in one of the thirteen boxes of MS
1600) is a sort of summary of some of the main points of "A Guess at the
Riddle." In addition, it includes a discussion of Peirce's categories
applied to signs (a topic that had been projected for the unwritten second
chapter of the "Guess") and a comparison of his views, on the subject
of dramatic expression and the principles of being, with those of the
New York playwright and theater manager Steele MacKaye. The title of the
paper is one of the alternatives Peirce had considered for his projected
"One, Two, Three," which then became "A Guess at the Riddle."

P 439: The Monist 1 January 1891):161-76. [Also published
in CP 6.7-34.] This is the first of five papers (although at least one
more had been projected, and "The Reply to the Necessitarians" mentioned
in the headnote to item 22 should be considered a companion piece to that
item) in the Monist Metaphysical Series, in which Peirce fully applied
to metaphysical questions the evolutionary philosophy developed in "A
Guess at the Riddle." (The chapter on metaphysics in item 19 is a mere
outline.) The architectonic approach of the "Guess" is here explained
and defended, and Peirce examines a number of conceptions to determine
which ones "ought to form the brick and mortar of a philosophical system."
He then reviews many of the essential ideas of the "Guess," again using
his categories to organize his examination of different sciences and demonstrates
that philosophy requires thoroughgoing evolutionism, that mental phenomena
fall into three classes feelings, sensations of reaction, and general
conceptions), that the fundamental law of mental action is that feelings
and ideas tend to spread, and that "the one intelligible theory of the
universe is that of objective idealism, that matter is effete mind." Peirce
concludes that chance and continuity are two of the most fundamental ideas
on which to build a philosophical theory that is compatible with modern
science.

P 474: The Monist 2 (April 1892):321-37. [Also published
in CP 6.35-65; see also the companion piece to this item, Peirce's lengthy
"Reply to the Necessitarians" (6.588-618), a reply to two articles published
in the July and October 1892 issues by Paul Carus, editor of the Monist.]
In this paper, Peirce considers-and then rejects-the main arguments for
determinism, and he concludes that an element of absolute chance prevails
in the world. He names his anti-necessitarian doctrine 'tychism' and argues
that "tychism must give birth to an evolutionary cosmology, in which all
the regularities of nature and mind are regarded as products of growth."

P 477: The Monist 2 (July 1892):533-59. [Also published
in CP 6.102-63.] In this paper, Peirce develops his synechism, the doctrine
that continuity is "of prime importance in philosophy" and, according
to which, the one law of mind is that ideas tend to spread and to affect
other ideas but that, in spreading, they lose intensity as they gain generality.
From synechism, the doctrines of logical realism, objective idealism,
and tychism follow. Peirce also considers continuity from the standpoint
of mathematics (with reference to Cantor), and he isolates two fundamental
properties of a continuous series: Aristotelicity (every continuum contains
its limits) and Kanticity (every continuum is infinitely divisible); applying
the former to philosophy, he finds that consciousness essentially occupies
time. He also claims that the three principal types of mental action correspond
to the three main classes of logical inference.

P 480: The Monist 3 (October 1892):1-22. [Also published
in CP 6.238-71.] In this paper, Peirce applies his synechistic philosophy
to the mind-body problem or "the relation between the psychical and physical
aspects of a substance." In order to carry out his purpose of developing
a philosophy that adequately represents the state of knowledge in the
nineteenth century, he discusses at length, and in elaborate technical
detail the constitution of matter and the molecular theory of protoplasm.
He associates the main physical properties of protoplasm with the three
main types of mental action, and he suggests that-as "matter is effete
mind," as "physical events are but degraded or undeveloped forms of psychical
events," and as "mechanical laws are nothing but acquired habits, like
all the regularities of mind"-"the idealist has no need to dread a mechanical
theory of life." Peirce ends his paper with a discussion of the life of
ideas and the self-consciousness of groups of individuals.

P 521: The Monist 3 (January 1893):176-200. [Also published
in CP 6.287-317.] In this fifth (and last) Monist paper, Peirce develops
his agapism, the doctrine that the law of love is operative in the world.
He argues that of the three kinds of evolution (by fortuitous variation,
by mechanical necessity, and by creative love) the third is the most fundamental:
"Love, recognizing germs of loveliness in the hateful, gradually warms
it into lift, and makes it lovely. That is the sort of evolution which
every careful student of my essay 'The Law of Mind' must see that synechism
calls for." Peirce delivers a polemic against the "gospel of greed" and
laments the fact that sentiment seems to have lost favor; sentimentalism,
he says, is "the doctrine that great respect should be paid to the natural
judgments of the sensible heart," and he entreats his readers "to consider
whether to contemn it is not of all blasphemies the most degrading." He
compares some of the views expressed here with those of Christianity,
and ends with a discussion of the continuity of mind and the caution that
we should not overestimate the importance of the individual.